Rep Power: 0

2003 Civic Hydrid.

I had a P1166 code, which as I understand it is the LAF (AirFuel/Flow sensor, top of manifold) so purchased a Denso 234-9005 to replace it, the original was a Denso as well. It cleared the P1166 code bit now throws a P0134 code.

Note, car does not have a rough idle, and seems to run fine, might be a little down on power.

The old sensor measure open circuit across the 2 back wires, which I believe are for the heater circuit, the new one measure about 1.17ohms, so seems good.
I think the P1166 is a faulty heater circuit, which validates my reading of open circuit on the old sensor, and the P0134 is now indicating a low or no signal from the new sensor, which is odd, so do I have a faulty sensor?

I think the hybrid has a third O2 sensor on the cat.